1. Field of the Invention
The present invention relates to a holder manufacturing method for loading a substrate of a semiconductor manufacturing device, a batch type boat having the holder, a loading/unloading method of a semiconductor substrate using the same, and a semiconductor manufacturing device having the same.
2. Description of the Prior Art
Generally, a semiconductor manufacturing device for treating the semiconductor substrate divides into a batch type including a boat for loading substrates in bulk therein in order to improve the processing capacity and a single wafer type for treating the process one by one in order to extremely decrease the processing time.
In these processes, since the process time is consumed in order to increase or decrease the processing temperature, a semiconductor manufacturing device of the batch type is generally used in the manufacturing process thereof, especially a process of high temperature.
FIG. 1A is an explanatory view illustrating an external appearance of a semiconductor manufacturing device including a batch type boat for loading a plurality of semiconductor substrates.
Referring to FIG. 1A, the conventional semiconductor manufacturing device of the batch type includes a reaction chamber of a tubular type for treating the semiconductor manufacturing process having a receiving space therein and an opening portion at lower portion thereof, and a boat 1 for loading the substrate and stacking the plurality of semiconductor substrates vertically.
Here, the semiconductor substrates 100 located at a cassette 3 mounted on a stage are transferred to the boat 1 through an end-effector 2.
The boat 1 includes the plural boat frames 4 of a pole type, a plurality of supporting grooves (slits) formed along the boat frames 4 at a predetermined interval, and a plurality of holders 7 for loading the semiconductor substrates inserted in the supporting grooves.
At this time, the boat 1 further includes a front opening portion 5 in regard to the working path (drawing in and out) of the end-effector 2 through the boat frame 4 (note FIG. 1B).
That is, the boat frame 4 occupies a half circle on the circumference thereof and the front opening portion 5 occupies the remaining portion in order to allow the loading/unloading of the semiconductor substrate 100.
Also, the boat 1 further includes a boat cap capable of supporting the lower portion thereof and opening and closing the opening portion of the reaction chamber. The boat 1, in which the loading operation is completed, is putted into the reaction chamber through a lifting up and down device.
Generally, the holder 7 for supporting the semiconductor substrate 100 is mounted on the boat 1.
That is, it is necessary to mount the holder 7 on account of the characteristic of the heat treatment and the large diameter of the semiconductor substrate. Since the transformation of the semiconductor substrate starts at about 750° C. and the temperature of the reaction chamber is beyond the temperature, it is necessary to locally support 0.7 R (Radius) of the semiconductor substrate so as to prevent its fall.
More concretely, the semiconductor process in the reaction chamber includes the heat treatment process. For example, there are a deposition process, a heat treatment process for removing a COP (crystal originated particle), a diffusion process (well drive-in) for diffusing the dopant added to the semiconductor for doping into the semiconductor substrate, a oxide forming process of the semiconductor substrate and a SOI heat treatment process and so on. At this time, the environment of high temperature is required.
The large diameter (about 12 inch) of the semiconductor substrate is positively performed in order to improve the productivity of the semiconductor. Also, the supporting method of the semiconductor substrate is changed in the heat treatment process according to the process of the high temperature and the large aperture.
That is, since the transformation of the semiconductor substrate starts at about 750° C., the local support on the circumference of the wafer in the boat 2 brings about the fall of the semiconductor substrate.
Especially, in the course of the heat treatment process, a slip, which is a crystallization defect of a silicon lattice of the semiconductor substrate, can be more easily occurred on account of the large apeture of the wafer. In order to prevent this problem, the holder is used. The holder supports the lower portion located at 0.7 R (Radius) of the semiconductor substrate thereon so as to prevent its fall.
The material of the holder 7 is made of a ceramic type for example, a silicon carbide (SiC) so as to cope with the environment of high temperature and the chemical environment of the reaction process. Also, a supporting ring 9 for a target-support of the 0.7 R is formed at the supporting panel 8 of a circular plate type similar to the shape of the semiconductor substrate
However, the conventional holder 7 brings about the manufacturing inconvenience on account of the manufacturing difficulty of the holder itself. Also, in order to supplement it, a peripheral device is used. However, there are various problems owing to the complexity of the peripheral device and so on.
FIG. 2 is a conceptual view illustrating a manufacturing method of the conventional holder. As shown in FIG. 2a as one example, the silicon carbide is mixed with a binder and it is precisely molded in the form of a holder. Here, since the binder includes impurities, the silicon carbide is coated on the mold surface of the holder type to complete the holder operation.
As shown in FIG. 2b as another example, the silicon carbide is thickly coated on a molding panel of a circular plate type and its circumference is cut and then, the molding panel (graphite) is incinerated. Thereafter, in order to form the supporting ring 9 on the silicon carbide panel, it is precisely treated again to complete the holder.
However, since the manufacturing methods of the conventional holder uses the silicon carbide of a high-price, there is a problem in that the productivity of semiconductor manufacturing device is deteriorated.
Also, the height of the supporting ring 9 is restricted on account of the occupying space of the supporting panel 8 and the supporting ring 9 of the holder.
Especially, where the semiconductor substrate 100 is seated on the holder 7, the holder 7 and semiconductor substrate 100 have one occupying space and it is necessary to consider the pitch of one unit and the working space of the end-effector 2 together.
In the batch type boat, the compact arrangement capable of minimizing the pitch is linked with the productivity (amount of the substrate treatment) of the semiconductor substrate 100.
As shown in FIG. 3, since the thickness of the holder 7 itself, that is, the thickness of the supporting panel 8 and the thickness of the supporting ring 9 and the working space “a” of the end-effector 2 of a robot arm between the holders 7 are ensured together, the pitch is increased, thereby decreasing the amount of the substrate treatment.
This problem is occurred in the top-edge-grip manner (FIG. 3a) and the bottom-lift manner (FIG. 3b) together. In order to load/unload the semiconductor substrate 100, it is necessary to ensure any thickness for ensuring the strength. At this time, it is also, necessary to ensure the working space “a” for inserting the end-effector 2 between the holders 7.
In case of the top-edge-grip type, the working space “a” for drawing in and out the end-effector 2 and the height of the supporting ring 9 for the working space of the grip should be ensured.
Accordingly, the total pitch “P” is the sum of the total thickness of the end-effector 2, the working space “a”, the thickness of the semiconductor substrate 100, the thickness of the supporting ring 9 and the thickness of the supporting panel 8 (note FIG. 3A).
In the meantime, in case of the bottom-lift type using the end-effector 2 of an U-shape, because the end-effector 2 is inserted between the supporting rings 9, the supporting ring 9 should be formed at a height providing the allowing space “a” equal to the total height of the end-effector 2. Accordingly, the pitch “P” is the sum of the lifting height and the thickness of the supporting panel (note FIG. 3B).
In the aspect of the working speed of the bottom-lift type, since the insertion process to the lower portion of the semiconductor substrate, the lifting process and the drawing-out process are performed in turns, the working speed is quickly and the gain of the pitch can be obtained in comparison with the top-edge-grip type. However, in case of using the silicon carbide so as to cope with the process of high-temperature, there is a problem in that the molding process for ensuring the height of the supporting ring is difficulty.
After all, the holder itself is complicated and the holder 7 having the supporting ring for performing the support of 0.7 R is required in the process of high-temperature for a large-diameter semiconductor, there are problems in that the manufacturing cost is high, the manufacturing process thereof is inconvenient and the productivity thereof is lowered.